Climate change is projected to displace upwards of 200 million refugees by 2050 (IPCC, 2018). States are increasingly conceptualising it as a ‘threat multiplier’ to national security. Meanwhile, ethnonationalist and authoritarian reactions to environmental concerns are increasingly prevalent within far-right ideology and discourse. In a global context of far-right ascendency and escalating ethnonationalist violence, climate change is triggering a worldwide intensification of militarised responses, alongside the rise of restrictive, carceral border regimes. I want to explore how carceral border regimes form part of a growing, systemic response to climate crisis that structurally enact and reinforce ethnonationalism. Through investigating the constitution of two detention sites where violent ethnonationalism intersects with ecological precarity – Australia’s asylum-processing site on Nauru; and the Rohingya refugee resettlement camp on Bhasan Char in Bangladesh – I will explore the convergence of ecology, migration and governance. In doing so, my research will fill a critical lacuna by investigating the structural manifestations of ethnonationalist responses to climate change, and contribute to understanding the ascendant forms of governance triggered by the climate crisis.